1. Field of the Invention
The invention is generally directed toward a collapsible umbrella, and more particularly toward an inexpensive, thermoplastic umbrella, having an integral cover or case, which when folded into the nested position forms a compact cylindrical shape.
2. Description of Related Art
The desirability of an inexpensive collapsible umbrella for limited use, on such occasions when protection from unexpected inclement weather is needed but the expense of a conventional umbrella is regarded as unjustified, has long been recognized.
U.S. Pat. No. 2,621,669 to Mayer shows a disposal umbrella made by cutting slits into two cardboard or plastic sheets to form the canopy support ribs and struts respectively, stapling the sheets together, and then curling the sheets to form the canopy support structure.
U.S. Pat. No. 3,177,883 to Militano shows a similar arrangement wherein the ribs and struts are formed together in a single plastic molding, and U.S. Pat. No. 3,564,679 to Meyer shows an improvement wherein the entire canopy support structure and the shaft of the umbrella are formed in a single injection molding.
A collapsible disposable umbrella made from thermoplastic, having an inner shaft and a canopy support structure disposed in a cylindrical hollow tube which acts as a protective case in the nested position and as a handle in the deployed position is shown in U.S. Pat. No. 4,821,756 to England.
In addition to being made from inexpensive materials such as plastic and being easily assembled, it is also desirable that a disposable umbrella be capable of being folded into a compact, durable, stackable configuration for storage, and be capable of being easily deployed when needed.
Thus, while various collapsible disposable umbrellas are known, they generally do not fold into a compact nested configuration but, to the contrary, fold into a configuration having a length which is at least equal to the length of a canopy support rib. In addition, most known disposable umbrellas do not fold into a nested configuration having a uniform diameter along the length of the umbrella shaft and are not, therefore, ideally suited for stacking. Moreover, when they are stacked or stored, they are susceptible to damage because the fabric is exposed. The England patent, which discloses a disposable umbrella disposed in a cylindrical tube, is well suited for stacking, but is not easily deployed. Deployment of the umbrella shown in the England patent requires first pulling the shaft and attached canopy support assembly from the tube, then sliding a lower hub member up along the shaft until it abuts an upper hub member, and finally reinserting the shaft, with the canopy extended, back into the tube.
According, the present invention provides an inexpensive plastic umbrella which, when folded or collapsed into a nested condition, assumes a compact, durable cylindrical shape having a cylinder length which is substantially shorter than the length of a radially extending rib assembly when the umbrella is in its deployed condition.